I. Field of the Invention
The present invention relates generally to the field of heat emitting devices. More particularly, the present invention relates to a unitary, composite, flexible, laminated infrared emissive module having redundant circuitry that is well suited for use as an infrared target.
II. Description of the Related Art
It is well known that objects having a surface temperature greater than absolute zero are capable of dissipating energy into the environment in the form of infrared radiation. Under certain circumstances, devices which emit infrared radiation can be utilized to heat objects or structures and can be utilized as a target for weaponry having infrared detection devices that "see" infrared emitting device's thermal signature.
In U.S. Pat. No. 4,250,398, Ellis et al. describe a solid state electrically conductive laminate. The laminate has a substantially continuous, electrically conductive layer of substantially uniform thickness comprised mainly of carbon that emits infrared radiation when an electric current is passed through it. This layer is specifically described as a homogeneous blend of about 60% to about 98% by weight of graphite, about 1.5% to about 20% by weight of manganese dioxide, and about 0.5% to about 20% by weight of zinc oxide. The electrically conductive layer is described as being applied to a flexible binder by silkscreen application. A pair of busbars having opposite electrical polarity arc placed in contact with the electrically conductive layer in varying arrangements. However, the busbars are not in a networked series-parallel power and ground plane circuit arrangement and if one of the busbars is dissected, major portions, if not all, of the electrically conductive layer cease to emit infrared radiation. The electrically conductive layer is disposed between a pair of barrier layers, which are additionally disposed between a pair of insulating layers.
Rosa, a co-inventor of U.S. Pat. No. 4,250,398 described above, in U.S. Pat. Nos. 4,422,646, 4,546,983 and 4,659,089 describes infrared targets likewise having a substantially continuous, electrically conductive layer of substantially uniform thickness comprised mainly of carbon that emits infrared radiation when an electric current is passed through it. The electrically conductive layer is not well described except that it is comprised mainly of carbon. This device also has a pair of busbars of opposite electrical polarity, except that each busbar is respectively connected at each end thereof to its mating electrical pole of an electrical source. This device likewise does not have a networked series-parallel power and ground plane circuit arrangement, and if one of the busbars is dissected, major portions, if not all, of the electrically conductive layer cease to emit infrared radiation. As a target, this device's usefulness is limited, because once the busbars have received a relatively few number of "hits" by a projectile fired by a weapon, it ceases to produce an even thermal signature. It appears that this device is improved over the device described by Ellis et al. only in that both ends of each busbar is connected to a respective pole of an electrical power source and does not have barrier layers.